[MsgPack] Added a convenience operator

[dbhaskaran]

Summary

Added "not equal to" operator for DocNode comparison

[dbhaskaran]

Moved from https://reviews.llvm.org/D81142 to use a different username.

[saiislam]

LGTM, thanks!

llvm/include/llvm/BinaryFormat/MsgPackDocument.h

friend bool operator<(const DocNode &Lhs, const DocNode &Rhs) {
     }
   }
 
   /// Equality operator
   friend bool operator==(const DocNode &Lhs, const DocNode &Rhs) {
     return !(Lhs < Rhs) && !(Rhs < Lhs);
   }
 
+  /// Inequality operator
+  friend bool operator!=(const DocNode &Lhs, const DocNode &Rhs) {
+    return !(Lhs == Rhs);
+  }
+
   /// Convert this node to a string, assuming it is scalar.
   std::string toString() const;
 
   /// Convert the StringRef and use it to set this DocNode (assuming scalar). If
   /// it is a string, copy the string into the Document's strings list so we do
   /// not rely on S having a lifetime beyond this call. Tag is "" or a YAML tag.
   StringRef fromString(StringRef S, StringRef Tag = "");
 

llvm/unittests/BinaryFormat/MsgPackDocumentTest.cpp

 //===- MsgPackDocumentTest.cpp --------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/BinaryFormat/MsgPackDocument.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
 using namespace msgpack;
 
+TEST(MsgPackDocument, DocNodeTest) {
+  Document Doc;
+
+  DocNode Int1 = Doc.getNode(1), Int2 = Doc.getNode(2);
+  DocNode Str1 = Doc.getNode("ab"), Str2 = Doc.getNode("ab");
+
+  ASSERT_TRUE(Int1 != Int2);
+  ASSERT_TRUE(Str1 == Str2);
+}
+
 TEST(MsgPackDocument, TestReadInt) {
   Document Doc;
   bool Ok = Doc.readFromBlob(StringRef("\xd0\x00", 2), /*Multi=*/false);
   ASSERT_TRUE(Ok);
   ASSERT_EQ(Doc.getRoot().getKind(), Type::Int);
   ASSERT_EQ(Doc.getRoot().getInt(), 0);
 }